Heads-up display mounts on brim of your cap

The goal here was to add some augmented reality to his field of vision. He went with a baseball cap because it’s a pretty easy way to strap something to your head. You can’t see it from this angle, but the setup requires you to cut a rather large hole in brim. The image from a smartphone (HTC Desire Z in this case) which is situated with the screen pointing toward [Matt’s] forehead. The screen reflects off of a small mirror, guiding the image down through a Fresnel lens mounted in the hole of the brim. The image is reflected a second time by the plastic in front of his eyes which is coated with a slightly mirrored material. Since the image is reflected twice it appears right-side up, and the use of the Fresnel lens places the image out about 20 cm in front of his view. He tried to get some images of the effect, but we think you’ve got to see it in person before passing judgement.

This does away with the need to track head movement (there’s a few hacks for that out there though). Augmented reality software is used to turn the view from the smartphone camera into overlay data for the display.

Sure, mounted on a hat this looks stupid, but if you took the camera, put it on the NOG mount of a combat helmet, and used a hinge to flip the display down, it would be much more awesome. It bypasses the hole-fresnel lens-reflection aspect, but combined with one of the transparent Samsung OLED displays recently featured here, it would be frickin’ awesome.

I’m no expert on optics, but couldn’t you keep the phone flat on the cap/lens by simply having the software render the image as if it were at a 45 degree angle (in 3D)?
The only downside is that you’d increase the aspect ratio, since there’s less usable screen, but it would improve the design’s aesthetics remarkably (and also allow for more flexibility in the angle of the mirrors.)

But those would be eye wear instead of head wear.
The advantage of the head wear solution over eye wear is that it doesn’t collide with existing eye wear (spectacles, shades…)
Also you can hang more weight on it when you need to.